Analysis of Corneal Spherical Aberration in Patients before and after Phacoemulsification

Purpose:To investigate the distribution and changes in corneal four-order spherical aberration Z40 in patients with age-related cataract before and after phacoemulsification,and to direct the application of aspherical intraocular lens (IOL)in PHACO combined with IOL implantation.Methods:A total of 155 eyes in 93 patients with age-related cataract were included.All patients received a comprehensive ophthalmologic examination.Corneal Z40 at a pupil diameter of 6 mm was measured by using a Scheimpflug photography system (Pentacam) preoperatively and 3 months postoperatively.Results:The mean corneal Z40 before and after the PHACO at a diameter of 6 mm was(0.294 ±0.138)μm and(0.271 ± 0.130)μm,respectively,with statistical significance(P<0.05, t =4.384).There was no significant difference between male (n=45, 76 eyes) and female patients (n=48,79 eyes) regard- ing corneal Z40 (t=-0.418,P=0.676).The corneal Z40 for patients (35 eyes) aged from 50 to 59 years was (0.238±0.104) μm preoperatively;(0.308 ±0.104)μm for 60 to 69 years; (0.332±0.151)μm for 70 to 79 years; and (0.307±0.164) μm for 80 to 89 years.A significant difference in Z40 was observed among different age groups.A linear positive correlation was noted between corneal Z40 and ages (r=0.203,P<0.003). Conclusion:The corneal Z40 varied significantly among cataract patients. Patients’ corneal Z40 , which should be considered when choosing aspherical IOL, increases slightly with age.Thus,customized aspheric IOLs are needed.